U/S anomalies and markers

Question 1

what are the uses of prenatal U/S? what can you eval wtih 3d? 4d?

Answer 1

viability, GA, chorionicity/amnionicity, fetal anomaly and evaluate for abn, fetal growth, identify high risk situations, guide invasive procedures, fetal echo, evaluate blood flow

3d: surface mostly
4d: movement

Question 2

what the body planes?

Answer 2

sagittal: midline (left and right)
coronal: divides top to bottom (ventral and dorsa/front and back)
transverse: divides cranial and caudal (top an bottom)

Question 3

what are some common misunderstandings with U/S?

Answer 3

dx/rule our chr abn
detects ALL birth defects
normal U/S = normal healthy baby
dx testing and targeted U/S provide same info
U/S equally sensitive for all things all times

Question 4

malformation:

Answer 4

poor formation of tissue (Cleft lip, CHD)

Question 5

deformation:

- disruption vs. dysplasia

Answer 5

unusual force on normal tissue

disruption: breakdown of normal tissue (amniotic bands)
dysplasia: abn organization of cells in tissue

Question 6

anomaly:

Answer 6

deviation from normal, structural change, birth defect

Question 7

soft marker:

Answer 7

finding that increase chance for a chromosome abn but AREN’T defects

Question 8

what are some 1st trimester U/S markers for Down syndrome? 2nd tri?

Answer 8

1st: >95th%ile NT, absent or hypoplastic nasal bone
2nd: nuchal thickening, echogenic bowel, shorten humerus or femur, ICF, pyelectasis, hypoplastic 5th middle phalanx, mild ventriculomegaly, hypoplastic nasal bone, sandal gap, flattend facial profile

Question 9

what % of T21 fetus have at least on finding?

Answer 9

50-70%

Question 10

major anomalies associated with Down syndrome:

Answer 10

CHD, cystic hygroma, hydrops, PUV, duodenal atresia (double bubble), ompahloele, pyloric stenosis

Question 11

what are some 2nd tri markers in T18? anomalies?

Answer 11

CPC, mega cisterna magna, strawberry-shaped skull, single umbilical artery, polyhydramnios

CHD, CL/P, ONTDs, banana sign or lemon sign, omphaloele, cystic hygroma or thick nuchal fold, diaphragmatic hernia, renal anomalies, micrognathia, skeletal abn

Question 12

what markers can be seen with T13?

Answer 12

EIF, IUGR, pyelectasis, increased NT, single umbilical artery, poly or oligohydramnios, enlarged cisterna magna

Question 13

major anomalies seen with T13?

Answer 13

CHD, CNS abn (holoprosencephaly and/or ONTDs,), CL/P, urogenital anomalies, polycystic kidneys, omphalocele, cystic hygroma, polydactyly, overlapping fingers, club or rocker-bottom feet

Question 14

markers for monosomy X?

Answer 14

cystic hygroma (septated), fetal ascites, pleural effusion, CHD, renal anomalies (horshoe or pelvic kidney)

Question 15

markers for triploidy?

Answer 15

early onset IUGR, asymmetric IUGR with larger fetal head
CNSabn
increased NT
CHD
omphalocele
club foot
syndactyly
Large, cystic placenta (XXY)
Small placenta (XXX)

Question 16

who is a risk adjustment based on U/S useful for?

Answer 16

intermediate age group, intermediate risk from screening, low population risk

Question 17

what is a likelihood ratio?

Answer 17

chance for an outcome given presence of a finding vs. the chance of the same outcome wit that finding

Question 18

what findings have the highest LRs for Down syndrome?

Answer 18

nuchal thickening
echogenic bowl
short humerus

Question 19

how can you calculate a risk adjustment? shortcut

Answer 19

denominator of a priori risk/(LR)

Question 20

What condition is associated with CPCs?

Answer 20

slightly increased risk for trisomy 18

Question 21

how effective is U/S at detecting T21?

what is the common risk reduction factor used clinically?

Answer 21

50-70%

50% reduction

Question 22

what can abn NT measurement be associated with beside chr abn?

Answer 22

CHDs

single gene disorders (Noonan, SMA, 22qDS, CAH, SLOS)

fetal demise, other birth defects, maternal-fetal infection, normal variation